Predicting patient outcomes after treatment with immune checkpoint blockade: A review of biomarkers derived from diverse data modalities.

Immune checkpoint blockade (ICB) therapy targeting cytotoxic T-lymphocyte-associated protein 4, programmed death 1, and programmed death ligand 1 has shown durable remission and clinical success across different cancer types. However, patient outcomes vary among disease indications. Studies have identified prognostic biomarkers associated with immunotherapy response and patient outcomes derived from diverse data types, including next-generation bulk and single-cell DNA, RNA, T cell and B cell receptor sequencing data, liquid biopsies, and clinical imaging. Owing to inter- and intra-tumor heterogeneity and the immune system's complexity, these biomarkers have diverse efficacy in clinical trials of ICB. Here, we review the genetic and genomic signatures and image features of ICB studies for pan-cancer applications and specific indications. We discuss the advantages and disadvantages of computational approaches for predicting immunotherapy effectiveness and patient outcomes. We also elucidate the challenges of immunotherapy prognostication and the discovery of novel immunotherapy targets.

Tutorial: integrative computational analysis of bulk RNA-sequencing data to characterize tumor immunity using RIMA.

RNA-sequencing (RNA-seq) has become an increasingly cost-effective technique for molecular profiling and immune characterization of tumors. In the past decade, many computational tools have been developed to characterize tumor immunity from gene expression data. However, the analysis of large-scale RNA-seq data requires bioinformatics proficiency, large computational resources and cancer genomics and immunology knowledge. In this tutorial, we provide an overview of computational analysis of bulk RNA-seq data for immune characterization of tumors and introduce commonly used computational tools with relevance to cancer immunology and immunotherapy. These tools have diverse functions such as evaluation of expression signatures, estimation of immune infiltration, inference of the immune repertoire, prediction of immunotherapy response, neoantigen detection and microbiome quantification. We describe the RNA-seq IMmune Analysis (RIMA) pipeline integrating many of these tools to streamline RNA-seq analysis. We also developed a comprehensive and user-friendly guide in the form of a GitBook with text and video demos to assist users in analyzing bulk RNA-seq data for immune characterization at both individual sample and cohort levels by using RIMA.

Alternative fat: redefining adipocytes for biomanufacturing cultivated meat.

Cellular agriculture provides a potentially sustainable way of producing cultivated meat as an alternative protein source. In addition to muscle and connective tissue, fat is an important component of animal meat that contributes to taste, texture, tenderness, and nutritional profiles. However, while the biology of fat cells (adipocytes) is well studied, there is a lack of investigation on how adipocytes from agricultural species are isolated, produced, and incorporated as food constituents. Recently we compiled all protocols related to generation and analysis of adipose progenitors from bovine, porcine, chicken, other livestock and seafood species. In this review we summarize recent developments and present key scientific questions and challenges that need to be addressed in order to advance the biomanufacture of 'alternative fat'.

Hippo Signaling Pathway Regulates Cancer Cell-Intrinsic MHC-II Expression.

MHC-II is known to be mainly expressed on the surface of antigen-presenting cells. Evidence suggests MHC-II is also expressed by cancer cells and may be associated with better immunotherapy responses. However, the role and regulation of MHC-II in cancer cells remain unclear. In this study, we leveraged data mining and experimental validation to elucidate the regulation of MHC-II in cancer cells and its role in modulating the response to immunotherapy. We collated an extensive collection of omics data to examine cancer cell-intrinsic MHC-II expression and its association with immunotherapy outcomes. We then tested the functional relevance of cancer cell-intrinsic MHC-II expression using a syngeneic transplantation model. Finally, we performed data mining to identify pathways potentially involved in the regulation of MHC-II expression, and experimentally validated candidate regulators. Analyses of preimmunotherapy clinical samples in the CheckMate 064 trial revealed that cancer cell-intrinsic MHC-II protein was positively correlated with more favorable immunotherapy outcomes. Comprehensive meta-analyses of multiomics data from an exhaustive collection of data revealed that MHC-II is heterogeneously expressed in various solid tumors, and its expression is particularly high in melanoma. Using a syngeneic transplantation model, we further established that melanoma cells with high MHC-II responded better to anti-PD-1 treatment. Data mining followed by experimental validation revealed the Hippo signaling pathway as a potential regulator of melanoma MHC-II expression. In summary, we identified the Hippo signaling pathway as a novel regulator of cancer cell-intrinsic MHC-II expression. These findings suggest modulation of MHC-II in melanoma could potentially improve immunotherapy response.

Machine learning on syngeneic mouse tumor profiles to model clinical immunotherapy response.

Most patients with cancer are refractory to immune checkpoint blockade (ICB) therapy, and proper patient stratification remains an open question. Primary patient data suffer from high heterogeneity, low accessibility, and lack of proper controls. In contrast, syngeneic mouse tumor models enable controlled experiments with ICB treatments. Using transcriptomic and experimental variables from >700 ICB-treated/control syngeneic mouse tumors, we developed a machine learning framework to model tumor immunity and identify factors influencing ICB response. Projected on human immunotherapy trial data, we found that the model can predict clinical ICB response. We further applied the model to predicting ICB-responsive/resistant cancer types in The Cancer Genome Atlas, which agreed well with existing clinical reports. Last, feature analysis implicated factors associated with ICB response. In summary, our computational framework based on mouse tumor data reliably stratified patients regarding ICB response, informed resistance mechanisms, and has the potential for wide applications in disease treatment studies.

Reassessment of adipocyte technology for cellular agriculture of alternative fat.

Alternative proteins, such as cultivated meat, have recently attracted significant attention as novel and sustainable food. Fat tissue/cell is an important component of meat that makes organoleptic and nutritional contributions. Although adipocyte biology is relatively well investigated, there is limited focus on the specific techniques and strategies to produce cultivated fat from agricultural animals. In the assumed standard workflow, stem/progenitor cell lines are derived from tissues of animals, cultured for expansion, and differentiated into mature adipocytes. Here, we compile information from literature related to cell isolation, growth, differentiation, and analysis from bovine, porcine, chicken, other livestock, and seafood species. A diverse range of tissue sources, cell isolation methods, cell types, growth media, differentiation cocktails, and analytical methods for measuring adipogenic levels were used across species. Based on our analysis, we identify opportunities and challenges in advancing new technology era toward producing "alternative fat" that is suitable for human consumption.

TISMO: syngeneic mouse tumor database to model tumor immunity and immunotherapy response.

Syngeneic mouse models are tumors derived from murine cancer cells engrafted on genetically identical mouse strains. They are widely used tools for studying tumor immunity and immunotherapy response in the context of a fully functional murine immune system. Large volumes of syngeneic mouse tumor expression profiles under different immunotherapy treatments have been generated, although a lack of systematic collection and analysis makes data reuse challenging. We present Tumor Immune Syngeneic MOuse (TISMO), a database with an extensive collection of syngeneic mouse model profiles with interactive visualization features. TISMO contains 605 in vitro RNA-seq samples from 49 syngeneic cancer cell lines across 23 cancer types, of which 195 underwent cytokine treatment. TISMO also includes 1518 in vivo RNA-seq samples from 68 syngeneic mouse tumor models across 19 cancer types, of which 832 were from immune checkpoint blockade (ICB) studies. We manually annotated the sample metadata, such as cell line, mouse strain, transplantation site, treatment, and response status, and uniformly processed and quality-controlled the RNA-seq data. Besides data download, TISMO provides interactive web interfaces to investigate whether specific gene expression, pathway enrichment, or immune infiltration level is associated with differential immunotherapy response. TISMO is available at http://tismo.cistrome.org.

Microstructured Hyaluronic Acid Hydrogel for Tooth Germ Bioengineering.

Tooth loss has been found to adversely affect not just masticatory and speech functions, but also psychological health and quality of life. Currently, teeth replacement options include dentures, bridges, and implants. However, these artificial replacement options remain inferior to biological replacements due to their reduced efficiency, the need for replacements, and the risk of immunological rejection. To this end, there has been a heightened interest in the bioengineering of teeth in recent years. While there have been reports of successfully regenerated teeth, controlling the size and shape of bioengineered teeth remains a challenge. In this study, methacrylated hyaluronic acid (MeHA) was synthesized and microstructured in a hydrogel microwell array using soft lithography. The resulting MeHA hydrogel microwell scaffold resembles the shape of a naturally developing human tooth germ. To facilitate the epithelial-mesenchymal interactions, human adult low calcium high temperature (HaCaT) cells were seeded on the surface of the hydrogels and dental pulp stem cells (DPSCs) were encapsulated inside the hydrogels. It was found that hydrogel scaffolds were able to preserve the viability of both types of cells and they appeared to favor signaling between epithelial and mesenchymal cells, which is necessary in the promotion of cell proliferation. As such, the hydrogel scaffolds offer a promising system for the bioengineering of human tooth germs in vitro.

Multidomain Geriatric Screen and Physical Fitness Assessment Identify Prefrailty/Frailty and Potentially Modifiable Risk Factors in Community-Dwelling Older Adults.

INTRODUCTION: Frailty begins in middle life and manifests as a decline in functional fitness. We described a model for community frailty screening and factors associated with prefrailty and frailty and fitness measures to distinguish prefrail/frail from robust older adults. We also compared the Fatigue, Resistance, Ambulation, Illnesses and Loss of weight (FRAIL) scale against Fried frailty phenotype and Frailty Index (FI). MATERIALS AND METHODS: Community-dwelling adults ≥55 years old were designated robust, prefrail or frail using FRAIL. The multidomain geriatric screen included social profiling and cognitive, psychological and nutritional assessments. Physical fitness assessments included flexibility, grip strength, upper limb dexterity, lower body strength and power, tandem and dynamic balance and cardiorespiratory endurance. RESULTS: In 135 subjects, 99 (73.3%) were robust, 34 (25.2%) were prefrail and 2 (1.5%) were frail. After adjusting for age and sex, depression (odds ratio [OR], 2.90; 95% confidence interval [CI], 1.05-7.90; P = 0.040) and malnutrition (OR, 6.07; 95% CI, 2.52-14.64; P <0.001) were independently associated with prefrailty/frailty. Prefrail/frail participants had significantly poorer performance in upper limb dexterity (P = 0.030), lower limb power (P = 0.003), tandem and dynamic balance (P = 0.031) and endurance (P = 0.006). Except for balance and flexibility, all fitness measures differentiated prefrail/frail from robust women. In men, only lower body strength was significantly associated with frailty. Area under receiver operating characteristic curves for FRAIL against FI and Fried were 0.808 (0.688-0.927, P <0.001) and 0.645 (0.546-0.744, P = 0.005), respectively. CONCLUSION: Mood and nutrition are targets in frailty prevention. Physical fitness declines early in frailty and manifests differentially in both genders.

An accelerometry and observational study to quantify upper limb use after stroke during inpatient rehabilitation.

OBJECTIVES: The objectives of the study are to characterize paretic upper limb (UL) use in people with different levels of impairment 4 weeks poststroke and to compare accelerometry and direct observational approaches. METHODS: Twelve stroke inpatients (five mild, three moderate, and four severe UL impairment) were recruited from a rehabilitation hospital. UL use was measured using accelerometry (24 hr) and direct observation (12 hr of behavioural mapping). Accelerometry variables included duration of use, use ratio, magnitude ratio, bilateral magnitude, and variation ratio. Direct observation recorded the duration of use and type of UL movement (e.g., functional vs. non-functional). RESULTS: From accelerometry data, people with mild, moderate, and severe UL impairments used their paretic UL 59%, 45%, and 22% of a 24 hr-day, respectively. People with severe UL impairment had the lowest paretic UL use duration (median 1.49 hr/day), magnitude ratio, and variation ratio compared with people with mild and moderate UL impairment. From 12 hr of observational data, people with mild impairment were using their UL for 37.8% of the observed time, whereas the people with moderate and severe impairment were using their UL 15.8% and 4.9%, respectively. UL movements for the mild cohort were mainly functional, whereas UL movements of the moderate and severe cohorts were mainly non-functional. UL movements were predominantly active for the mild and moderate cohorts but passive for the severe cohort. Duration of paretic UL use from accelerometry and observation data were highly correlated (ICC > 0.8), but the absolute percentage error between methods ranged from 34.2% to 42.7%. CONCLUSIONS: Paretic UL use within the first 4 weeks poststroke differs across levels of impairment in this exploratory study. Accelerometry and observation findings of paretic UL use were correlated and may be needed in different situations as they capture different information.

Pharmacokinetics of human recombinant C1-esterase inhibitor and development of anti-drug antibodies in healthy dogs.

Complement-mediated intravascular hemolysis occurs in canine immune-mediated hemolytic anemia (IMHA). Complement inhibitors such as recombinant C1 esterase inhibitor (rC1-INH) might prevent this process and alter the disease course. This study aimed to characterize the pharmacokinetics of a single 500 IU IV dose of rC1-INH in 8 healthy beagle dogs, evaluate the dogs for any adverse effects of drug administration, and determine whether rC1-INH administration induces anti-drug antibody formation. Serum rC1-INH concentrations were measured using a commercial functional ELISA at baseline and at 10, 20, 40, 60, 80, 100, 120, 240, 360, 480, 600, 720, 960, and 1440 min post drug administration. Complete blood counts were conducted at baseline, 720 and 1440 min. Western blot analysis, using rC1-INH as the target antigen was used to detect anti-drug antibodies in 14-day serum samples. No adverse clinical reactions were noted following rC1-INH administration. Pharmacokinetic modelling suggested that the peak C1-INH concentration achieved is 0.21 IU/mL and that C1-INH concentration is significantly greater than baseline for 100 min following injection. A robust antibody response was detected which suggests that rC1-INH should not be re-administered after an initial course. Clinical trials of rC1-INH in dogs with intravascular IMHA are now warranted.

Development of a plasminogen activator inhibitor (PAI-1) assay and comparison of plasma PAI-1 activity in hyperlipidemic/dyslipidemic dogs with either hyperadrenocorticism or diabetes mellitus, and healthy dogs.

Thrombosis is a serious complication of many canine diseases and may be related to decreased fibrinolytic potential. Plasminogen activator inhibitor-1 (PAI-1) is the key regulator of fibrinolysis with increased levels demonstrated in states of pro-thrombosis and abnormal lipid metabolism. Our objective was to develop and validate a canine PAI-1 activity assay and test whether dogs with hyperadrenocorticism or diabetes mellitus that are hyperlipidemic/dyslipidemic have increased plasma PAI-1 activity. Functionally active PAI-1 in the plasma sample was incubated with recombinant tissue plasminogen activator (tPA), allowing the formation of a 1:1 stoichiometric inactive complex. Residual unbound tPA was then reacted with excess plasminogen in the presence of a colorimetric plasmin substrate. Plasmin production is quantified by computing the area under the curve of time (x) vs optical density (y) plot and converted to tPA IU/mL by comparison to a calibration curve of tPA standards. PAI-1 activity was determined by calculating the proportion of exogeneous tPA suppressed by PAI-1 in plasma. Assay verification included assessment of linearity, specificity, precision, sensitivity, and stability. PAI-1 activity was increased in hyperlipidemic compared to healthy dogs, but there was no significant difference between dogs with hyperadrenocorticism and diabetes mellitus. A near significant decrease in activity was detected in thawed plasma stored for 20h at 4°C. Our successfully validated assay offers a new tool for investigating fibrinolysis in dogs. Investigation of PAI-1 activity in dogs with other diseases associated with an increased risk of thrombosis would be valuable. Future studies of PAI-1 activity should consider its lability.

Development and Application of a Microfluidics-Based Panel in the Basal/Luminal Transcriptional Characterization of Archival Bladder Cancers.

In the age of personalized medicine stratifying tumors into molecularly defined subtypes associated with distinctive clinical behaviors and predictable responses to therapies holds tremendous value. Towards this end, we developed a custom microfluidics-based bladder cancer gene expression panel for characterization of archival clinical samples. In silico analysis indicated that the content of our panel was capable of accurately segregating bladder cancers from several public datasets into the clinically relevant basal and luminal subtypes. On a technical level, our bladder cancer panel yielded robust and reproducible results when analyzing formalin-fixed, paraffin-embedded (FFPE) tissues. We applied our panel in the analysis of a novel set of 204 FFPE samples that included non-muscle invasive bladder cancers (NMIBCs), muscle invasive disease (MIBCs), and bladder cancer metastases (METs). We found NMIBCs to be mostly luminal-like, MIBCs to include both luminal- and basal-like types, and METs to be predominantly of a basal-like transcriptional profile. Mutational analysis confirmed the expected enrichment of FGFR3 mutations in luminal samples, and, consistently, FGFR3 IHC showed high protein expression levels of the receptor in these tumors. Our bladder cancer panel enables basal/luminal characterization of FFPE tissues and with further development could be used for stratification of bladder cancer samples in the clinic.

Targeted biomarker profiling of matched primary and metastatic estrogen receptor positive breast cancers.

Patients with newly diagnosed, early stage estrogen receptor positive (ER+) breast cancer often show disease free survival in excess of five years following surgery and systemic adjuvant therapy. An important question is whether diagnostic tumor tissue from the primary lesion offers an accurate molecular portrait of the cancer post recurrence and thus may be used for predictive diagnostic purposes for patients with relapsed, metastatic disease. As the class I phosphatidylinositol 3' kinase (PI3K) pathway is frequently activated in ER+ breast cancer and has been linked to acquired resistance to hormonal therapy, we hypothesized pathway status could evolve over time and treatment. Biomarker analyses were conducted on matched, asynchronous primary and metastatic tumors from 77 patients with ER+ breast cancer. We examined whether PIK3CA and AKT1 alterations or PTEN and Ki67 levels showed differences between primary and metastatic samples. We also sought to look more broadly at gene expression markers reflective of proliferation, molecular subtype, and key receptors and signaling pathways using an mRNA analysis platform developed on the Fluidigm BioMark™ microfluidics system to measure the relative expression of 90 breast cancer related genes in formalin-fixed paraffin-embedded (FFPE) tissue. Application of this panel of biomarker assays to matched tumor pairs showed a high concordance between primary and metastatic tissue, with generally few changes in mutation status, proliferative markers, or gene expression between matched samples. The collection of assays described here has been optimized for FFPE tissue and may have utility in exploratory analyses to identify patient subsets responsive to targeted therapies.

Expression and nucleotide diversity of the maize RIK gene.

The K homology (KH) domain is a conserved sequence present in a wide variety of RNA-binding proteins. The rough sheath2-interacting KH domain (RIK) protein of maize has been implicated in the maintenance of the repressed chromatin state of knox genes during leaf primordia initiation. The amino acid sequences of the publicly available plant RIK proteins contain a splicing factor 1 (SF1)-like KH domain core sequence motif that distinguishes them from all other SF1-like KH domain-containing proteins. We demonstrate that the maize RIK gene exhibits surprisingly little nucleotide sequence diversity among Zea species and subspecies. Microarray hybridization experiments demonstrate that RIK has a higher level of expression in the shoot apical meristem as compared with 14-day seedling. Reverse transcriptase-polymerase chain reaction analysis of RIK indicates that the gene is expressed in many tissues, albeit at lower levels in older leaf samples. Taken together, these data suggest that the RIK protein may be involved in the maintenance of an inactive chromatin state of knox and possibly other genes in nonmeristematic tissues.

The effect of genetically engineered spider silk-dentin matrix protein 1 chimeric protein on hydroxyapatite nucleation.

Spider silks exhibit remarkable mechanical properties while dentin matrix protein 1 provides controlled nucleation and hydroxyapatite growth. In the present work, these two attributes were combined via genetic engineering to form a chimera, a clone encoding consensus repeats from the major protein in the spider dragline silk of Nephila clavipes fused to the carboxyl terminal domain of dentin matrix protein 1 (CDMP1). The objective was to exploit the self-assembly and material properties of silk proteins with controlled hydroxyapatite (HA) formation from CDMP1, for novel biomaterial composites. The purified recombinant protein retained native-silk like self-assembly properties and beta-sheet structure when formed into films and treated with methanol. When the chimeric protein in solution was incubated with CaCl(2,) the secondary structure shifted from random coil to alpha-helix and beta-sheet, due to the interactions between the CDMP1 domain and Ca(2+). The control protein without the CDMP1 domain did not undergo a similar transition. Films formed from the recombinant protein were mineralized using simulated body fluids and induced the formation of calcium-deficient carbonated HA, Ca(10)(PO(4))(6)(OH)(2) based on SEM, EDS, FTIR and TEM analysis. This mineral phase was not formed on the films formed from the control spider silk protein without the CDMP1 domain. Considering the osteoconductivity of HA and the novel material features of spider silks, these new hybrid systems offer potential as biomaterials for a number of potential applications.

Intrinsic fluorescence changes associated with the conformational state of silk fibroin in biomaterial matrices.

Silk fibroin is emerging as an important biomaterial for tissue engineering applications. The ability to monitor non-invasively the structural conformation of silk matrices prior to and following cell seeding could provide important insights with regards to matrix remodeling and cell-matrix interactions that are critical for the functional development of silk-based engineered tissues. Thus, we examined the potential of intrinsic fluorescence as a tool for assessing the structural conformation of silk proteins. Specifically, we characterized the intrinsic fluorescence spectra of silk in solution, gel and scaffold configurations for excitation in the 250 to 335 nm range and emission from 265 to 600 nm. We have identified spectral components that are attributed to tyrosine, tryptophan and crosslinks based on their excitation-emission profiles. We have discovered significant spectral shifts in the emission profiles and relative contributions of these components among the silk solution, gel and scaffold samples that represent enhancements in the levels of crosslinking, hydrophobic and intermolecular interactions that are consistent with an increase in the levels of ss-sheet formation and stacking. This information can be easily utilized for the development of simple, non-invasive, ratiometric methods to assess and monitor the structural conformation of silk in engineered tissues.

Childhood emotional abuse and neglect as predictors of psychological and physical symptoms in women presenting to a primary care practice.

OBJECTIVE: There were two aims to this study: first to examine whether emotional abuse and neglect are significant predictors of psychological and somatic symptoms, and lifetime trauma exposure in women presenting to a primary care practice, and second to examine the strength of these relationships after controlling for the effects of other types of childhood abuse and trauma. METHOD: Two-hundred and five women completed the Childhood Trauma Questionnaire (Bernstein et al., 1994), Trauma History Questionnaire (Green, 1996), the Symptom Checklist-revised (Derogatis, 1997), and the Revised Civilian Mississippi Scale for posttraumatic stress disorder (Norris & Perilla, 1996) when presenting to their primary care physician for a visit. Hierarchical multiple regression analyses were conducted to examine unique contributions of emotional abuse and neglect variables on symptom measures while controlling for childhood sexual and physical abuse and lifetime trauma exposure. RESULTS: A history of emotional abuse and neglect was associated with increased anxiety, depression, posttraumatic stress and physical symptoms, as well as lifetime trauma exposure. Physical and sexual abuse and lifetime trauma were also significant predictors of physical and psychological symptoms. Hierarchical multiple regressions demonstrated that emotional abuse and neglect predicted symptomatology in these women even when controlling for other types of abuse and lifetime trauma exposure. CONCLUSIONS: Long-standing behavioral consequences may arise as a result of childhood emotional abuse and neglect, specifically, poorer emotional and physical functioning, and vulnerability to further trauma exposure.

Family of shuttle vectors for ruminal Bacteroides.

A family of shuttle plasmids was constructed for genetic transformation of Escherichia coli and of ruminal Bacteroides strains AR20 and AR29. Plasmids were based on the replicon from Bacteroides plasmid pBI191 and were designed for studies of chromosomal integration (pBA), for the identification and study of Bacteroides gene promoters (pPPR) and for the expression of heterologous genes in Bacteroides (pBAC). Electroporation efficiency of Bacteroides was up to 10(5) transformants/microg plasmid, depending on the source of the DNA. The largest plasmid, pBA, was maintained at approximately 8 copies per cell in AR20 and did not measurably alter in vitro growth of transformed cells. In the current work, pBA did not integrate into the chromosomes of AR20 or AR29. The ability of plasmid pPPR to select promoter sequences was demonstrated by removal and replacement of promoters that activate the clindamycin resistance gene. The suitability of pBAC for expression of heterologous genes was demonstrated by expression of the Moraxella species fluoroacetate dehalogenase gene H1 to give intracellular activity of 7 nmol fluoride released/min/mg soluble protein in AR20 and 4 nmol/min/mg in AR29. Spontaneous loss of pBAC under non-selective conditions was 0.11-0.165% per generation, significantly less than loss of the native Bacteroides plasmid pBI191, which was lost at 0.53% per generation.

The cortisol and glucocorticoid receptor response to low dose dexamethasone administration in aging combat veterans and holocaust survivors with and without posttraumatic stress disorder.

BACKGROUND: Because alterations in cortisol negative feedback inhibition associated with aging are generally opposite of those observed in posttraumatic stress disorder (PTSD), we examined the cortisol and glucocorticoid receptor (GR) response to dexamethasone (DEX) in older trauma survivors. METHODS: Twenty-three Holocaust survivors (9 men, 14 women), 27 combat veterans (all male), and 10 comparison subjects (7 men, 3 women) provided samples for plasma or salivary cortisol and glucocorticoid receptor determination in mononuclear leukocytes at 8:00 AM on the day of, and following, 0.5 mg of DEX at 11:00 PM. RESULTS: Greater percent suppression of cortisol and lymphocyte GR was observed in older trauma survivors with PTSD compared to survivors without PTSD and comparison subjects. There was a significant main effect of depression in the direction of reduced suppression following DEX, consistent with the effects of DEX in major depressive disorder patients. Responses to DEX were uncorrelated with PTSD symptom severity, but cortisol suppression was associated with years elapsed since the most recent, but not focal, traumatic event. CONCLUSIONS: The response to DEX is generally similar in older and younger trauma survivors, but the findings suggest that age, symptom severity, and lifetime trauma exposure characteristics may influence this response.